const express = require('express')
const rTracer = require('cls-rtracer')

const app = express()
// any third party middleware that does not need access to request ids goes here
// ...

app.use(rTracer.expressMiddleware())
// optionally, you can override default middleware config:
// app.use(rTracer.expressMiddleware({
//   useHeader: true,
//   headerName: 'X-Your-Request-Header'
// }))

// all code in middlewares, starting from here, has access to request ids

// an example middleware for a generic find entity endpoint
app.get('/api/v1/entity/{id}', (req, res, next) => {
  entityService.find(req.params.id)
    .then((entity) => {
      // you can obtain the request id here
      const requestId = rTracer.id()
      console.log(`requestId: ${requestId}`)
      
      res.json(entity)
    })
    .catch(next)
})

// an imaginary entity-service.js
async function find (entityId) {
  // you can obtain the request id here
  const requestId = rTracer.id()
  // ...
}

const fastify = require('fastify')()
const rTracer = require('cls-rtracer')

// any third party plugin that does not need access to request ids goes here
// ...

fastify.register(rTracer.fastifyPlugin)
// optionally, you can override default plugin config:
// fastify.register(rTracer.fastifyPlugin, {
//   useHeader: true,
//   headerName: 'X-Your-Request-Header'
// }))

// all code in plugins or handlers, starting from here, has access to request ids

// an example handler for a generic find entity endpoint
// router config is skipped for the sake of simplicity
app.get('/test', async (request, reply) => {
  const entity = await entityService.find(request.params.id)
  // you can obtain the request id here
  const requestId = rTracer.id()
  console.log(`requestId: ${requestId}`)

  reply.send(entity)
})

// an imaginary entity-service.js
async function find (entityId) {
  // you can obtain the request id here
  const requestId = rTracer.id()
  // ...
}

fastify.use(rTracer.fastifyMiddleware())

const Koa = require('koa')
const rTracer = require('cls-rtracer')

const app = new Koa()
// any third party middleware that does not need access to request ids goes here
// ...

app.use(rTracer.koaMiddleware())
// optionally, you can override default middleware config:
// app.use(rTracer.koaMiddleware({
//   useHeader: true,
//   headerName: 'X-Your-Request-Header'
// }))

// all code in middlewares, starting from here, has access to request ids

// an example middleware for a generic find entity endpoint
// router config is skipped for the sake of simplicity
app.use(async (ctx) => {
  const entity = await entityService.find(req.params.id)
  // you can obtain the request id here
  const requestId = rTracer.id()
  console.log(`requestId: ${requestId}`)

  ctx.body = entity
})

// an imaginary entity-service.js
async function find (entityId) {
  // you can obtain the request id here
  const requestId = rTracer.id()
  // ...
}

const Hapi = require('@hapi/hapi')
const rTracer = require('cls-rtracer')

const init = async () => {
  const server = Hapi.server({
    port: 3000,
    host: 'localhost'
  })
  // any third party plugin that does not need access to request ids goes here
  // ...

  await server.register({
    plugin: rTracer.hapiPlugin
  })

  // optionally, you can override default middleware config:
  //  await server.register({
  //    plugin: rTracer.hapiPlugin,
  //    options: {
  //      useHeader: true,
  //      headerName: 'X-Your-Request-Header'
  //    }
  //  })

  // all code in routes, starting from here, has access to request ids
}

init()

// an example route for a generic find entity endpoint
server.route({
  method: 'GET',
  path: '/test',
  handler: async (request, h) => {
    const entity = await entityService.find(request.params.id)
    // you can obtain the request id here
    const requestId = rTracer.id()
    console.log(`requestId: ${requestId}`)

    return entity
  }
})

// an imaginary entity-service.js
async function find (entityId) {
  // you can obtain the request id here
  const requestId = rTracer.id()
  // ...
}

const { createLogger, format, transports } = require('winston')
const { combine, timestamp, printf } = format

// a custom format that outputs request id
const rTracerFormat = printf((info) => {
  const rid = rTracer.id()
  return rid
    ? `${info.timestamp} [request-id:${rid}]: ${info.message}`
    : `${info.timestamp}: ${info.message}`
})

const logger = createLogger({
  format: combine(
    timestamp(),
    rTracerFormat
  ),
  transports: [new transports.Console()]
})

// mixin function adds properties of the returned object to the logged JSON.
const logger = require('pino')({
    mixin () {
        return { requestId: rTracer.id() }
    }
})

{
  // Add request id to response header (default: false).
  // If set to true, the middleware/plugin will add request id to the specified
  // header. Use headerName option to specify header name.
  echoHeader: false,
  // Respect request header flag (default: false).
  // If set to true, the middleware/plugin will always use a value from
  // the specified header (if the value is present).
  useHeader: false,
  // Request/response header name, case insensitive (default: 'X-Request-Id').
  // Used if useHeader/echoHeader is set to true.
  headerName: 'X-Request-Id',
  // A custom function to generate your request ids (default: UUID v1).
  // The function will receive the intercepted request (as-is from the framework
  // being used) as its first argument. The returned id could be a usual string,
  // or a number, or any custom object, like in the example below.
  // Ignored if useHeader is set to true.
  requestIdFactory: (req) => ({
    id: 'Your request id',
    customHeader: req.headers['X-Custom-Header']
  }),
  // Use request id generated by Fastify instead of generating a new id.
  // Only available for the Fastify plugin.
  useFastifyRequestId: false,
}

const rTracer = require('cls-rtracer')

rTracer.runWithId(() => {
  console.log(rTracer.id()) // id is available here
  setInterval(() => {
    console.log(rTracer.id()) // and here
  }, 1000)
})

// you may override id by providing the 2nd argument
rTracer.runWithId(() => {
  // ...
}, 42) // 42 is the id override here

// async/await syntax is also supported, as `runWithId()`
// returns the result of `fn`
await rTracer.runWithId(myAsyncFn)